diff --git a/internal/controller/mantlebackupconfig_controller.go b/internal/controller/mantlebackupconfig_controller.go
index 8150cc27..db13f966 100644
--- a/internal/controller/mantlebackupconfig_controller.go
+++ b/internal/controller/mantlebackupconfig_controller.go
@@ -234,15 +234,19 @@ func (r *MantleBackupConfigReconciler) createOrUpdateCronJob(ctx context.Context
 			"--namespace", mbc.GetNamespace(),
 		}
 		container.ImagePullPolicy = corev1.PullIfNotPresent
-		container.Env = []corev1.EnvVar{
-			{
-				Name: "JOB_NAME", ValueFrom: &corev1.EnvVarSource{
-					FieldRef: &corev1.ObjectFieldSelector{
-						FieldPath: "metadata.labels['batch.kubernetes.io/job-name']",
-					},
-				},
-			},
+
+		if len(container.Env) == 0 {
+			container.Env = append(container.Env, corev1.EnvVar{})
+		}
+		env := &container.Env[0]
+		env.Name = "JOB_NAME"
+		if env.ValueFrom == nil {
+			env.ValueFrom = &corev1.EnvVarSource{}
+		}
+		if env.ValueFrom.FieldRef == nil {
+			env.ValueFrom.FieldRef = &corev1.ObjectFieldSelector{}
 		}
+		env.ValueFrom.FieldRef.FieldPath = "metadata.labels['batch.kubernetes.io/job-name']"
 
 		return nil
 	})